Rate Adaptive Windowing
Congestion window consists of reserved part (RWND) and variable part (CWND)
RWND equals reserved rate times estimated RTT
CWND tries to estimate residual capacity and share it with other active connections
In fast recovery, set CWND to RWND + (CWND-RWND)/2
In slow start, set CWND to RWND + 1, set SSTHRESH to minimum of RWND + (CWND-RWND)/2 and AWND
Scale window increase by (CWND-RWND)/CWND
Sender still sends minimum of CWND and AWND
Size of receiver’s buffer must be at least equal RWND to sustain reserved rate using TCP